The present invention generally relates to an adaptive interface for use with a microcomputer and, in particular, relates to such an interface having means for selecting the operating mode thereof.
The advent of the microcomputer has revolutionized many industries, not the least of which is the telecommunication industry. The telecommunication industry has been impacted first by the increasing plethora of subscriber devices to which service must be extended; and second, by the available microcomputers that can be integrated into the present and future switching systems to provide the services demanded.
Historically, telecommunication switching systems have been centralized, i.e. a central computer is provided to set up and tear down all communication paths, execute all protocol conversions and provide all maintenance and monitoring services. However, the centralized architecture has, inter alia, the severe drawback of catastrophic failure to every subscriber in the event of component failure in the central exchange. In addition, in order to update or modernize such a central exchange a very costly redesign of the entire network is usually necessary. Clearly, such centralized systems are generally unable to maintain pace with technological advancements such as the microcomputer.
The spectre of a paralytic catastrophe lead to the development of a distributively controlled switching network wherein a digital switching network is provided with a plurality of autonomous terminal interfaces. The autonomous terminal interfaces are then connected to a plurality of subscribers. In such a distributively controlled network the terminal interfaces are provided, usually via a microcomputer, with the command and control instructions necessary to establish communication links between subscribers of different terminal interfaces as well as among subscribers to the same terminal interface. Thus, the spectre was dispelled since any failure at any terminal interface produced only a minimal effect with regard to the overall subscribers to the network. One such distributively controlled switching network is the ITT System 12 Digital Exchange.
Nevertheless, as the development of microcomputers and switching systems continues there is an increases need for an interface to a microcomputer that can be adapted to permit microcomputers of different capabilities to be interconnected to, for example, a switching apparatus.